Why don't dungeon and raid bosses do damage based on a percentage of your health?

Seriously, why don't they? I believe having this be the mechanic would have several positive influences on the game:

a) It would keep old content relevant and prevent its obsolescence.

You could potentially visit any dungeon in the world of previous expansions and still find it challenging, rewarding and worthwhile provided of course your damage was scaled down. This is better for new players in my opinion because it gives them a wealthy pool of content to do and experience.
People have said and indeed Blizzard themselves have said that they want us doing the current content. Why exactly? There are so many dungeons and raids out there that are not being used at the moment and I believe that is a big shame. Also the current content is miniscule in comparison to all dungeon/raid content that exists out there.

Then there is the argument by Blizzard that creating hard content that will be experienced by only a small portion of the player base is financially unviable. I find this interesting, especially seeing how 90% of the dungeon and raid content of the game is ignored now.

b) It would stop gear from being a factor determining your chances of success when attempting a boss

and would instead make the fight entirely skill based so you couldn't use lack of time as an excuse to do a raid any more. Granted, this would apply more to smaller raids, not 14 boss ones.

c) It would obviate the need to have multiple difficulty levels of the same dungeon.

This is due to the fact that the challenge presented by the fight would be equal for everybody, regardless of your gear (i.e. health pool), since 20% of 20.000 or 300.000 is the same in relative terms - you still lose 1/5 of your health. I find the current model a bit overblown because you do the same dungeon ad nauseam due to all the different difficulty settings since gear has such an impact on your performance in the higher levels of difficulty. By the end of it all, you're bored stiff.

Because this game is about character progression, and if your gear doesnt matter, there's no character progression. no need for gear. - for the same reason even PVP has gear still.

Pretty much this. If people want to go run the old content as a "challenge" which it isn't any more with spell alterations over time, you can run it when level appropriate. Everyone suddenly seems to want to end character progression in an RPG... you're playing the wrong game.

Some raid encounters do have damage based on your hp, making them hard or impossible to solo.

"Religion is an insult to human dignity. With or without it, you'd have good people doing good things and evil people doing bad things, but for good people to do bad things, it takes religion." - Steven Weinberg, Nobel Laureate in physics

Pretty much this. If people want to go run the old content as a "challenge" which it isn't any more with spell alterations over time, you can run it when level appropriate. Everyone suddenly seems to want to end character progression in an RPG... you're playing the wrong game.

Maybe they could add some new twist to those old dungeons to make running them worthwhile progression-wise.

I see B as a negative. There's no sense of progression if your character doesn't get stronger. Also being able to get a bit of extra gear to make a boss easier is very important for people to progress at all.

Also C is just not true, the different difficulty levels are important for players of different skill, and are not just there for progression. A lot of flex only or LFR only raiders don't have the skill to kill heroic bosses. And that's also why the best guilds clear raids in very significantly worse gear than most other people.

Also C is just not true, the different difficulty levels are important for players of different skill, and are not just there for progression. A lot of flex only or LFR only raiders don't have the skill to kill heroic bosses. And that's also why the best guilds clear raids in very significantly worse gear than most other people.

But there could be easier and harder dungeons which would be different from each other and not just 4 iterations of the same instance.

It wouldn't. Old content becomes obsolete once people have beaten it. There are only so many times you can expect a player to repeat an encounter before they grow bored of it and want to try something new.

That being said, the concept of challenge modes is one way of milking old content a bit more. Which is fine, but it's not for everyone.

Originally Posted by Santoryu

b) It would stop gear from being a factor determining your chances of success when attempting a boss

As I said above, WoW has challenge modes to provide this kind of challenge. But that isn't for everyone. In fact challenge mode stuff is specifically aimed at a very small minority of the players.

The whole progression model of WoW in general is based around the idea that your character gets more powerful and therefore able to defeat stronger opponents. It's important that gear is a factor in determining success when attempting a boss, because gear continues to improve even after you have reached a skill plateau.

Broadly generalised, there are 3 major factors that determine a raid's ability to beat a boss:
1) Player Skill: This improves over a long time. The more skill a player has, the more they suffer from the laws of diminishing returns.
2) Boss Experience: As a group fights a boss they learn the fight and get better at execution. As time goes on, the laws of diminishing returns start to have an effect as the group moves towards perfect execution.
3) Gear: This improves steadily over time.

So what you have in any raid encounter is a fight that starts out beating the players. But the players rapidly learn the fight and get closer to beating it. Each week they will come back, but their ability to improve their performance by execution decreases. Often this means a group will take months to get sufficiently good to beat the encounter. This is where gear comes in. Every week the raid gets stronger through gear, effectively bringing them closer to success.

Originally Posted by Santoryu

c) It would obviate the need to have multiple difficulty levels of the same dungeon.

The need for multiple difficulty levels stems from the vast spectrum of player skill and ability. Currently the game has 3 raid difficulties for just this reason. Flex is laughably easy (and therefore boring) for any hardcore guild. But heroic raids are impossible for 99% of players.

So what you have in any raid encounter is a fight that starts out beating the players. But the players rapidly learn the fight and get closer to beating it. Each week they will come back, but their ability to improve their performance by execution decreases. Often this means a group will take months to get sufficiently good to beat the encounter. This is where gear comes in. Every week the raid gets stronger through gear, effectively bringing them closer to success.

This is quite sensible actually

The need for multiple difficulty levels stems from the vast spectrum of player skill and ability.

But wouldn't it be better to have easy and hard dungeons rather than easy and hard versions of the same one?

There are only so many times you can expect a player to repeat an encounter before they grow bored of it and want to try something new.

Isn't this also a consequence of running the same dungeon multiple times on different difficulty levels, which to be fair aren't all that dissimilar.

In this fantasy scenario, the best gear for tanks to wear would be whatever had the lowest stam on it. Dungeon blues would trump raiding gear hands down, possibly even leveling greens. Healers would have a much easier time keeping a green geared tank up than a heroic raid geared tank.

I'm sure there's many many more flaws in such a system, but It's too morning for braining.

The first would be the complete removal of stamina. It would no longer be useful since the 100% can not be improved upon.

The second would be that if we're doing this solely based on Raid Bosses, then we'd have to balance two measures of health. % for bosses and and an actual numerical measure for outside questing. Unless you suggest turning every ability in the game % based, which would be a huge undertaking.

And finally, if it is percentage based, even without crit immunity, DPS and healers would be able to absorb potentially lethal mechanics.

But wouldn't it be better to have easy and hard dungeons rather than easy and hard versions of the same one?

Assuming infinite resources, yes. In reality though, this would simply result in half the number of dungeons for any given player.

What is better, 2 dungeons, each available on 2 difficulty settings, or 1 of them only available on easy, and 1 of them only available on hard?

Originally Posted by Santoryu

Isn't this also a consequence of running the same dungeon multiple times on different difficulty levels, which to be fair aren't all that dissimilar.

Undoubtedly, running a dungeon X number of times on various difficulty settings before you run on it the hard setting is going to mean players will last less long on the hard modes. That being said, making 3 different raids to get the player to not burn out on the hard raid encounters means 3 times as much work, or, more realistically, a third of the bosses in each difficulty.

Use SoO as an example. Imagine wing 1 was offered only for LFR, Wing 2 only for Flex, Wing 3 only for normal and Wing 4 only in Heroic. Sure, in this case running LFR ten times is not to going to make you bored of the bosses you fight in Heroic mode. But with only 3 bosses, how long is Heroic mode going to keep you busy before you get bored anyway?

In this fantasy scenario, the best gear for tanks to wear would be whatever had the lowest stam on it. Dungeon blues would trump raiding gear hands down, possibly even leveling greens. Healers would have a much easier time keeping a green geared tank up than a heroic raid geared tank.

A very good point - something I never really considered.

But with only 3 bosses, how long is Heroic mode going to keep you busy before you get bored anyway?

We could have 3 7 boss raids per tier. But that might be taxing on the devs.